Method of maintaining a dental varnish dispenser in usable condition



R L. FORTNEY METHOD OF MAINTAINING DENTAL VARNISH DISPENSER IN USABLIECONDITION Jan. 3, 1939.

Filed April 25, 1956 INVENTOR.

ATTORNEY.

Patented Jan. 3, 1939 UNITED STATES PATENT OFFEQE NEETHOD F MAINTAININGA DENTAL VAR- NISH DISPENSER IN USABLE CONDITION 1 Claim.

This invention relates to improvements in the art of using dentalvarnish or the like.

In the filling of teeth, after the dentist has drilled out the cavityand before inserting the filling therein, it is necessary to coat theinterior of the cavity with a lining of varnish. This dental varnish isnow purchased in small bottles and is applied to the cavity either bydipping a small wire loop into the varnish or by immersing cotton in thevarnish and applying the cotton to the cavity. These methods areunsatisfactory as the varnish hardens on the instruments and renderscleaning difiicult. Furthermore, because of frequency of use, the bottlecontaining the varnish has to be kept open most of the time and a largepercentage of the liquid evaporates or gums up before it can be used sothat only a relatively small part of the bottle is actually employed inthe dental work.

It is a general object of the present invention to provide an improvedmethod of using dental varnish or the like whereby said varnish may bedischarged into a cavity or other location by a syringe or likeinstrumentality, and whereby the syringe needle is so protected afteruse as to prevent solidification of the varnish in and around the needleduct.

A more specific object of the invention is to provide a method of usingdental varnish which includes the steps of discharging the varnish by asyringe, and the prevention of solidification of the varnish in the ductof the syringe needle by immersing the needle end in liquid which iscapable of preventing solidification of the varnish, and by hermeticallysealing said needle end and liquid from the atmosphere.

A further object of the invention is to provide improved apparatus foreffecting commercial exploitation of the above method.

A more specific object of the invention is to provide a syringe having achamber adapted to contain dental varnish or the like, having a tubularneedle with its inner end communicating with said chamber and with itsouter end projecting exteriorly thereof, and having means for ejectingvarnish from said chamber through said needle, and to provide means formaintaining the varnish fiuent in and around the duct of the needle whenthe device is not in use, comprising an auxiliary container havingliquid therein which is capable of preventing solidification of thevarnish, and a closure for said auxiliary container through which theouter end of the needle may be removably inserted, said closure beingformed of material capable of forming a self -seal around the needle.

With the above and other objects in view, the invention consists ofimprovements in the art of using dental varnish or the like and all itsparts 3 and combinations as set forth in the claim and all equivalentsthereof.

In the accompanying drawing in which the same reference numeralsdesignate the same parts in all of the views:

Fig. l is a side view of a syringe showing how it may be used todischarge varnish into a drilledout cavity;

Fig. 2 is a fragmentary side view of the syringe showing the needle endabout to be inserted into the auxiliary container;

Fig. 3 is a longitudinal sectional view through the auxiliary containerand the outer end of the syringe showing the manner of preventingsolidification of the varnish in and around the syringe needle when thedevice is not in use;

Fig. 4 is a longitudinal sectional view through the syringe, thedot-and-dash lines indicating how the outer end of he syringe may beopened for the purpose of inserting a cartridge therein;

Fig. 5 is a longitudinal sectional view through one of the syringecartridges; and

Fig. 6 is a side view of a modified form of syringe comprising acollapsible tube.

Referring more particularly to the drawing, 3 the numeral iii designatesthe tubular body portion of the syringe, said tubular body having itsouter end provided with a projecting threaded stem H (see Fig. 3)through which a duct l2 extends. A tubular needle l3 extends through aif coupling member is, and said coupling member has an interiorlythreaded part l5 which is cooperable with the threaded stem l i of thesyringe body I!) as shown in Fig. 3. When the coupling member is inposition, the inner end of the needle 83 extends through the duct 5 2and into the body portion it of the syringe. The outer end of the needle55 projects exteriorly of the coup-ling memher.

The other end of the tubular body I 0 is adapted to be closed by a headI7, and said head has forwardly projecting spaced extensions I8 whichare pivotally connected to the sides of the tubular body it as at E9.Within the head I! is a tubular member having an annular shoulder 2|engageable with a coil spring 22 (see Fig. 4), and the inner end of saidtubular member is formed with an enlarged recess 23.

A plunger 24 is slidable through the tubular member 20 and has its innerend extending into the syringe body portion l0 and formed with a head25. The outer end of the plunger may be fitted with a knob 26. Bypulling the plunger outwardly until its head 25 engages in the recess 23to move the tubular member 28 against the tension of the spring 22, theentire head and plunger may be pivoted to the dot-and-dash line positionof Fig. 4 to open the barrel.

A cartridge 21 (see Fig. is furnished with varnish 28 therein, and saidcartridge has one end closed by a stopper 2!! formed of rubber or othermaterial capable of forming a self-seal around the inner end of theneedle when said inner end of the needle extends there-through. Theother end of the cartridge is closed by a resilient member 30 whichforms a piston.

When the head of the syringe is moved to the dot-and-dash line positionof Fig. 4, the cartridge may be inserted in the barrel of the syringe,and it is pushed against the inner end of the needle until the needlehas passed through the rubber stopper 29 as shown in Fig. 4. The syringehead and plunger are then pivoted back to operative position, andmovement of the plunger will act on the piston 30, closing one end ofthe cartridge to force varnish 28 from the cartridge into the needle 13.

While syringes of this type are well known, they have always been usedfor injecting liquids which do not gum up. To use a syringe of thistype, however, as ordinarily furnished, for dis charging varnish isentirely unsatisfactory as the varnish will gum up in the very smallpassage way of the needle l3 and prevent further use.

It is a part of the present invention, however, to make it entirelypractical to utilize a syringe for injecting dental varnish, andaccordingly there is provided an auxiliary container or vial 3! filledpreferably with varnish. The material in the auxiliary container may,however, be a suitable solvent capable of preventing solidification ofthe varnish within the needle duct and around the end of the needle. Theend of the vial is hermetically sealed by a stopper 32 of rubber orother pierceable material capable of forming a self-seal around theneedle when the needle is inserted therein.

With this arrangement as soon as the dentist has finished using asyringe, the needle end is immediately inserted through the stopper 32as shown in Fig. 3 so that it projects into the varnish or other liquidin the vial iii. The rubber stopper 32 forms a tight seal around theneedle and prevents any air from getting into the auxiliary container.Furthermore, the varnish or solvent in the auxiliary container preventsgumming up of the end of the needle and also keeps the duct within theneedle in open condition. No matter how the device is laid down, theduct of the needle will always be kept clear, as varnish will eitherflow from the cartridge 2'! of the syringe into the needle ducts or fromthe auxiliary container into the needle duct.

As shown in Fig. 6, a more simple type of syringe may be employed, andin this figure the syringe consists merely of a collapsible metal tube33 containing the dental varnish, said tube being provided with atubular needle 34 projecting from one end through which the varnish maybe discharged by merely squeezing the tube. Whenever the syringe 33 isnot in use, the needle 34 is inserted in the auxiliary container 3| inthe same manner heretofore described and shown in Fig. 3, and it istherefore contemplated that the collapsible tube type of syringe belikewise equipped with an auxiliary container containing varnish orsolvent therefor. 1

The form of invention shown in Fig. 6 would be well adapted for variousother uses besides the discharging of dental varnish. It is particularlywell adapted for use as a container for liquid glue, as one of the maindifliculties in the merchandising of glue at the present time is thegumming up of the glue around the openings of the bottles or othercontainers. It is therefore contemplated that wherever the term varnishis used in the claim, that this term comprehends any other materialwhich readily gums up when exposed to the air. It is further to beunderstood that the term syringe as used in the claim comprehends anyinstrumentality or the types shown in Fig. 1 or 6, or of any other typewherein ma terial may be forcibly discharged through a tubular needle.

From the above it is apparent that the present invention discloses avery practical method of merchandising varnish or like material, and itis further apparent that the invention will readily appeal to anydentist, as he will no longer have to bother with cleaning theinstruments used to apply varnish to a cavity, and will be able to usethe varnish until it is entirely exhausted; whereas, heretofore, it wasnecessary to throw away a large part of each bottle of varnish due tothe fact that it had solidified before it was used up.

Although only two forms of the invention have been shown and described,it is obvious that various other changes and modifications may be madewithout departing from the spirit of the invention, and all of suchchanges are contemplated as may come within the scope of the claim.

What I claim is:

The method of maintaining a dental varnish dispenser in usablecondition, said dispenser being a syringe of a type having a tubularneedle of minute bore through which varnish may be ejected withouthaving the primary pressure applying means contact the varnishcomprising pierceably inserting the syringe needle through the sealingmeans of an auxiliary container which is hermetically sealed by apierceable resilient sealing means and which contains liquid capable ofpreventing solidification and gumming of the varnish in the syringeneedle when the latter is immersed therein, whereby a syringe having atubular needle of minute bore may be employed for injecting the varnishinto a cavity and whereby the varnish may be prevented from solidifyingin the needle and in the syringe for indefinite periods betweensuccessive uses of the syringe.

RUFUS L. FORTNEY.

